Show LAND vaccination interesting imperl made in france and one of the t things in recent science has to do with the vaccina aion of land everyone knows says he press that it enriches instead of impoverishes afield to plant it with a leguminous crop such as clover or lucerne the roots of which lave a power of absorbing and retaining more nitrogen than they take from the ground hut where the nitrogen c kincs from is another matter the air suggested itself at once alien people begun to tudy the problem and lawes and gilbert among others spent many months in fruitless endeavors to trace the source to the air coming at last to a negative con elusion the discovery was eventually anade by hellriegel nell riegel and will barth of germany that the absorption was due to minute organisms a sort of disease in the roots which when alie supply of nitrogen in the soil began to fail appeared in the form of small excrescences crescen ces drew nitrogen from the air and so caused the enrichment when this had once been settled it became a matter of importance to foster and if possible hasten the growth of the disease in the fields sown with and extensive experiments have been made in france and germany with aliis object fields have been literally vaccinated vaccina ted by sprinkling over them soil in which crops have been grown or even water in which aliey have been soaked in a tract of old peaty land vas sown with clover and vac with about one and a half tons to the acre of an old clover field scarcely any kotlier manure at all was used A more convincing experiment still was performed in prussia eliere a large field was sown with dupins and divided one part being treated in the ordinary fashion the other inoculated from an old lupin crop the yield in alie latter part was five and a half times as great as that under alie normal treatment A remarkable point in these operations is that each variety of the leguminous ae lias its characteristic microbe and that it is no use inoculating a field of clover for instance with lucerne or of lupin with clover |